


Alone Together (Until We Aren't)

by Ursa_Tattoo



Series: Cosmo Armstrong AU [1]
Category: The LEGO Movie (2014)
Genre: (it's a rewrite of tlm2's ending but with cosmo so it's kinda gay and even fucking sadder), Alternate Universe, Angst, Back-to-the-Futuring, Canon Divergence, Dudes Being Gay, Hurt/Comfort, M/M, Undar!Benny, guys being dudes
Language: English
Status: Completed
Published: 2019-07-06
Updated: 2019-07-06
Packaged: 2020-06-22 05:20:58
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 1,079
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/19660654
Author URL: https://archiveofourown.org/users/Ursa_Tattoo/pseuds/Ursa_Tattoo
Summary: for rnainframe's Cosmo Armstrong AU.It's not the fading away that scares them. It's fading away from each other.





	1. Breaking Away

**Author's Note:**

> This fic features an AU version of Benny that got stuck in Undar all alone like Rex did; the AU belongs to rnainframe on tumblr, I just help him with it and write things for him. Go look at the 'cosmo armstrong' tag on his blog for more info!

This time around, Undar wasn't so lonely. Double the victims, double the tormentors. Each trying to break their past self, in tandem. Partners in crime, that's what they called themselves.

But... that's not the end, even if both Cosmo and Rex intend for it to be.

The stiffness of the real world melts away into the fantasy as... Emmet and Benny's _friends_ arrive. Lucy helps up Emmet, Metalbeard helps up Benny, and Unikitty hops up to nuzzle them both.

Rex and Cosmo... don't know what to make of it.

"...You came back for them," Rex breathes, his voice quiet. His voice _Emmet's._

"That's not _possible_." Cosmo's starting to look... fidgety.

The reunions between the friends are brief, as Rex and Cosmo bond together, throwing off the brief uncertainty as Rex starts to laugh.

"You think you've _stopped_ us? We can go back and do it alllll over again, until we get it right and you become _us_ ," Rex sneers.

"We're inevitable," Cosmo adds, ready to press the button on his time machine to start it all over again.

But Lucy's prepared, tossing out that little heart shaped bomb.

"Goodbye!" It squeaks as it explodes, sending Rex and Cosmo flying and destroying what remains of their temporal technology.

Cosmo's helmet is shattered beyond repair, the pieces falling off of his face as he starts to hyperventilate. Emmet moves forward to comfort him, but stops when Rex glares.

Rex moves close to Cosmo, holding him and rubbing circles into his back. "It's okay, you can breathe, you've done it before." His voice isn't quite Emmet's, but it's softer. Truer. Cosmo's breathing eases.

Once Cosmo's calmer, Emmet speaks up. "You two can stay with us, you know. You don't have to be the bad guys."

"...It doesn't work like that," Cosmo rasps.

Benny tilts his head curiously, but he comes to the conclusion before Emmet does, eyes widening in horror. "No, you're not..."

Rex nods. "Got it in one. You two didn't become us, so we can't exist anymore." He holds up his hand, which is starting to look translucent, and he weakly smiles. "Like in Back to the Future."

"You'll know what that is when you're older," Cosmo remarks, cutting off Emmet and Benny's question.

"...You can't just disappear, please," Emmet pleads, trying to take Rex's hand, then Cosmo's, only to pass through like they're made of air.

"Don't worry about us, kid, we'll be fine, back in our own... timelines." Rex's eyes widen in horror at the same moment that Cosmo's do, and the two stare at each other with the sickly realization.

"...You're not from the same timeline?" Emmet's words sound silly even to himself.

"...no, we're not." Cosmo almost sounds like Benny, in that moment, and Rex clings onto him for dear life.

"You can't... _We_ can't..." Rex can't even make a full sentence, and as he and Cosmo start to dissipate further, he looks like he's on the verge of a breakdown.

Cosmo's mental state isn't any better, and he clings onto Rex just as tightly. "I can't be alone again--"

"Neither can I, we have to-- You can't leave, we can't fade away like this!" Rex sounds truly frantic, and he and Cosmo don't seem to be aware that anyone is still there as they cling onto each other.

"Fuck, it'll... We'll find each other again, okay? We have to, we can't..." Cosmo's shaking.

"We will, we have to, I don't..." Rex holds Cosmo's hand, while he still has a hand to hold.

"...we'll always have been partners," Cosmo stammers.

"...partners." Rex pauses. "Cosmo, I--" The fading gets faster and Rex panics. "No! I still have more that I want to--"

And Rex is gone.

"Rex!!" Cosmo tries to hold the space that Rex used to occupy, but then Cosmo is gone too.

All that remains of the two bad futures are memories, and the echoes of their screams.


	2. Pulling Together

Rex wakes up after the end of his world back on Undar.

His head's throbbing like he got punched in the face, and for a second, he can't remember anything. What happened? He'd been with... Cosmo.

_Cosmo._ Fuck.

Rex's temporary hazy calm splinters as he remembers. Their past selves. They'd been rescued. And then they'd...

_"Cosmo, I--" 'I think I love you.'_

Fuck.

...Love hadn't been on the table, and now Cosmo's in a whole other _timeline._ He can make a new time machine, easy. No problem. None at all, but finding the right timeline? That's harder.

He stands, a little shaky, and winces at a stabbing pain in his side. When he reaches down, his fingers come away red, but he feels something lodged there. He pulls it out, no hesitation, and inspects, only to have his breath catch.

Red glass.

Cosmo's helmet had been destroyed.

It's a link to him. To his timeline.

Maybe this won't be so hard.

-

It takes some time to make a new time machine, and even longer to analyze the glass to find its origin, but he manages. He's Rex Dangervest, he always does.

Blasting through to a totally separate timeline is harder than going to the past, but it's possible, and he does it. Punches his way through without a thought, without a regret.

Space is vast, but he'd know the Cosmonaut anywhere, and he dons his space suit, blasting out to the smaller ship and banging on the glass. Not with his full strength, but enough to get attention and see Cosmo's face light up.

He enters the ship easily, same as the first time, but this time, there's no tension. Only release, as Rex and Cosmo cling to each other in a tight embrace.

"You-- you got here," Cosmo breathes into Rex's shoulder, and Rex grins, cuddling him close.

"I'm Rex Dangervest, not even time itself could keep me away." There's that cocky presentation, and Cosmo smiles at the familiarity.

"....I didn't want to leave." Cosmo's quiet.

"Neither did I." He pauses. "...You know, now that we're here, I've got something I really need to tell you..."

"Oh?"

"...I think I might love you." He pauses. "In a manly way, obviously."

"...I think I love you too." Cosmo flushes. "...Maybe more than in a manly way."

"...yeah, it might be more. Wanna kiss? Like bros do? ...Or more than bros do?"

"I thought you'd never ask."

Their mutual bitterness melts away in the sweetness of the kiss, and they entangle in the arms of their kindred spirits.


End file.
